Fix some statically detected code issues

This includes: unnecessary semicolons, suppress warnings, switch statements, final/private qualifiers, Optional wrapping, conditionals, both inline and non-inline variables, ternaries, Collection putAll() calls, StringBuilders, and throws declarations.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=244182539

javatests/google/registry/dns/writer/clouddns/CloudDnsWriterTest.java

@@ -425,7 +425,6 @@ public class CloudDnsWriterTest {
   }
 
   @Test
-  @SuppressWarnings("unchecked")
   public void retryMutateZoneOnError() {
     CloudDnsWriter spyWriter = spy(writer);
     // First call - throw. Second call - do nothing.